c++

vector::size_type in C++

size_type is a (static) member type of the type vector<int>. Usually, it is a typedef for std::size_t, which itself is usually a typedef for unsigned int or unsigned long long.

What does -> mean in C++?

It’s to access a member function or member variable of an object through a pointer, as opposed to a regular variable or reference. For example: with a regular variable or reference, you use the . operator to access member functions or member variables. But if you’re working with a pointer, you need to use the -> operator: It can also … Read more

Callback functions in C++

Note: Most of the answers cover function pointers which is one possibility to achieve “callback” logic in C++, but as of today not the most favourable one I think. What are callbacks(?) and why to use them(!) A callback is a callable (see further down) accepted by a class or function, used to customize the current logic … Read more

A warning – comparison between signed and unsigned integer expressions

It is usually a good idea to declare variables as unsigned or size_t if they will be compared to sizes, to avoid this issue. Whenever possible, use the exact type you will be comparing against (for example, use std::string::size_type when comparing with a std::string‘s length). Compilers give warnings about comparing signed and unsigned types because the ranges of signed and unsigned ints … Read more

libstdc++-6.dll not found

If you are using MingW to compile C++ code on Windows, you may like to add the options -static-libgcc and -static-libstdc++ to link the C and C++ standard libraries statically and thus remove the need to carry around any separate copies of those. Version management of libraries is a pain in Windows, so I’ve found this approach the quickest … Read more

How to trim a std::string?

EDIT Since c++17, some parts of the standard library were removed. Fortunately, starting with c++11, we have lambdas which are a superior solution. Thanks to https://stackoverflow.com/a/44973498/524503 for bringing up the modern solution. Original answer: I tend to use one of these 3 for my trimming needs: They are fairly self-explanatory and work very well. EDIT: BTW, I have std::ptr_fun in … Read more

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